The bladder is a hollow organ for receiving and storing urine before the urine is expelled from the body. The bladder typically comprises a multilayer wall including a mucus lining for resisting the corrosive effects of the urine and multiple muscle layers for contracting the bladder to expel the urine. Cancer and other disorders can form within the wall itself, either within an internal layer or between the layers, making treating the disorder difficult without invasive surgery. Similarly, the lining of the bladder can prevent treatment drugs administered within the bladder from penetrating deep enough into the wall to reach the diseased tissue. The disorders within the bladder wall can also make locating the treatment site itself difficult as the diseased tissue is often not readily visible from the interior or exterior of the wall.
One technique for treating disorders within the bladder wall is by navigating a catheter through the urethra into the interior of the bladder and dispensing the treatment drug proximately or topically to the bladder wall such that the treatment drug permeates into the wall to reach the diseased tissue. As the drugs must permeate through the outer layers of the wall to reach the diseased tissue, a highly concentrated solution or a large dosage must be administered to ensure that the treatment drug reaches the diseased tissue at a sufficient concentration to effectively treat the disorder. A similar drawback is that the treatment drugs can be dispersed over a large section of the bladder wall or diffuse into the healthy tissue surrounding the diseased tissue. In addition to wasting often expensive drugs on healthy tissue, the powerful drugs used for treating severely diseased tissue can also damage healthy tissue creating substantial complications.
Another technique includes incorporating a syringe or similar hollow tubed assembly into the catheter for penetrating the bladder wall and administering the treatment drugs directly into the diseased tissue within the bladder wall. Although this approach permits more accurate administration of the drug into the diseased tissue than permeation, estimating the depth of the syringe within the bladder wall can be difficult. As a result, the tip of the syringe can miss the diseased tissue resulting in ineffective drug delivery or puncture the bladder wall completely, thereby leading to serious complications. In addition, navigating the rigid needle or hollow tube through the urethra without damaging the side walls can be difficult.
As a result, there exists a need for additional techniques that treat diseased tissue within the bladder wall by accurately delivering treatment drugs into the bladder wall while minimizing the risk of complications from the procedure.